bowl gouge fouling

[Keithie]

I'm probably being stupid here ...but still havent figured this out.

1. My lathe centre is 6" above the bed
2. My bowl gouge is ground to about 45 degrees
3. When I start to hollow out the inside of a bowl I do so with my toolrest across the bed, parallel with the face of the bowl
4. I think the maths is that if your centre height is 6" and your bowl gouge is 45degrees then the pythagoras 'square on the hypotenuse...' thing means that if your bowl gouge is longer than 8.5" (about) then it wont fit. Mine, with handle, is a lot longer than 8.5"
5. I cant use my bowl gouge over bed without the bed getting in the way if I want to have bevel contact as I start a cut

This isnt a problem with my spindle gouge as its bevel angle is much less.

Obviously I cant be the only person to have found this problem with a bowl gouge...but possibly I'm the only one dumb enough not to have figured out how to deal with it!

I could grind down the metal of the bowl gouge and chop a lot of the handle off, of course, but (andI'm just guessing here) I doubt that's the most sensible solution!

What do most folk do please ?

 

[YewTube]

Go and watch the Brendan Stemp video at 15mins, in Finneyb's posting
Bill

 

[nev]

A pictures worth a thousand words etc... Post a pic of your gouge grind, we can see if theres anything obvious and maybe offer some hints and tips. Same goes for posting a video / youtube of the issue.

 

[CHJ]

Your Bowl Gouge should be being held very close to horizontal with the bed, handle perhaps 5-10 degrees below at the most.

The gouge should be presented on it's side with the bevel facing you so that the bevel is rubbing on the piece at somewhere between 9 and 10 o'clock on the wood.

The handle should be traveling in a horizontal arc parallel to, but across the bed.

If you have the gouge pointing up-hill to the extent the handle is fouling the bed then you are asking for a serious catch when it digs in.


The above is a simplification as regards precise angles of approach but are intended to show you are presenting the gouge incorrectly.

Look at how a bowl saver tool works, your bowl gouge needs to work in a similar plane to the cutters in those, but it needs the bevel to be facing you for support with the flute facing away from you.


You need to be removing wood from 9 o'clock to centre, with slight variations on that at the most with the tool swinging horizontally. The only thing you should be at risk of hitting is the tailstock centre if you have not moved it back out of the way.

 

[Keithie]

Thanks ...watched the video...very helpful and Chas's pics are excellent for showing the technique ...many thanks ...which is pretty much as per the (good parts of) the video. The catches I get are indeed anything other than small!

My bowl gouge grind is pretty much a standard (not swept back at all) type ...so not sure of that makes a diff?

Will try and post a pic of it (mutilated as it is by my freehand grinding ona white wheel!).

What I've been trying to do is kinda in line with this video ..

https://m.youtube.com/watch?v=Hliecq--lYw

where I start is with the gouge side and underside bevel rubbing and with my gouge handle out to the side of the bed and below it .. then raising the handle to start to make the cut and kinda hoping that it clears above the bed before it hits it ...lol...not a relable method ..quite aside from the outward skidding that can happen as I move out the diameter!

Obviously swinging the gouge horizontally across the bed rather than trying to combine vertical with the horizontal movement (to lift handle over bed) makes a lot more sense. So maybe the gouge grind or my technique (or quite possibly both!) need to be sorted.

 

[Keithie]

pic of bowl gouge grind (the white splodges are wood, not cleaned off yet)

 

[CHJ]

You only raise the handle to produce the cut on SPINDLE Work, even then a horizontal component of rotating the flute in the direction you are cutting is desirable for best control.

On Bowl inner and outer you precipitate the cut by moving the gouge horizontally or very nearly so, not by lifting it.

If you have the gouge rubbing with the flute facing upwards, not facing very near horizontal, then lifting the handle is guarantied to produce a catch as you have no means of, or time to react to the cutting edge diving into the wood and being forced deeper as the wood rotates.

To stop your gouge skating across the face of the bowl blank when starting a cut and have no bevel support, make a shallow groove with a parting tool or point of a skew held horizontally to provide a ledge for the bevel to engage on, the sharper your tool and getting correctly supported presentation at the start helps avoid the skating.

 

[Random Orbital Bob]

Or rest the back of the gouge against your thumb which is clamping the toolrest acting as a stop to the natural desire of the gouge to skate to the left.

 

[Keithie]

lol..oh dear, technique definitely not good then...thanks again Chas ... I wonderedwhy I was havingtrouble ...I was using my spindle gouge for spindle work then using the same technique ofloftingthe handle to cut on bowls ...then moved onto bowl gouges and was wondering why it didnt work!

Thanks also Bob, I'll try that too.

Will attempt to make a nice small bowl tonorrow with my new (/or at least forgotten) knowledge!

cheers
Keith

 

[selectortone]

As others have said... If the handle of your gouge is hitting the lathe bed you are presenting it to the work at the wrong angle. I had this problem when I was starting out. Sounds to me like your toolrest is too low (which was my problem). Try raising it a little. That will bring your gouge more to the horizontal. The toolrest should be just below centre height such that the centre of the tip of the gouge intersects with the centre of the bowl when the tool is horizontal.

 

[woodfarmer]

With bowls I tend to slide the head up the bead and work off the end without the tailstock present. (Not unlike a gynaecologist )

with straight or very steep sided bowls with a flat bottom the transition from side to base I find not so easy. it is then that I dip the handle and rotate the gouge to run on the bottom of the bevel then cut with an arc type movement way above centre height before working back to gouge on its side and horizontal to the centre height. shallow scooped bowls seem a lot easier.

I am not that experienced so may well be doing things wrong

 

[thelastgizmo]

I think the OP is having difficulty with where the bevel is supported. I've been doing the same! I thought the bevel should be supported under the gouge I. E at 6 o'clock position rather than at the side (9 oclock). I had my headstock rotated as my blank was larger than the throw of the lathe so didn't have his particular problem (fortunately no dig ins!). But I would have with the next bowl if I hadn't read this thread!

 

[Paul Hannaby]

On the inside of a bowl, The handle should start low at the outside of the bowl and should end up at a height where the cutting edge is at centre height at the centre of the bowl. Imagine the leading edge of the bowl gouge is working like a parting tool. That also starts high and ends up at centre height when it reaches the centre.

You can probably get an almost passable cut holding the bowl gouge horizontal just like you can if you hold a spindle gouge horizontal but neither are the best way to do it.

 

[Keithie]

Thanks ...seems like more than one way to skin a cat.

I've understood the bowl gouge a bit better (but by no means well!) and on some curves in some wood I can get a surprisingly good finish with it using the lightest touch..but I guess experience, as ever, is what counts in terms of adapting the way you cut to the shape and wood type/condition.

Funnily enough I'm still far more confident with a skew than a bowl gouge ...lol...must just be practice!

 

[CHJ]

Thanks ...seems like more than one way to skin a cat.

Once you have got the hang of supporting the gouges on the bevel so that you can control the depth of cut, then think about the introducing of a 'slicing' action as opposed to just a pushing 'chop' motion to a cutting edge will produce an easier cut and in most instances a cleaner cut.

Think in terms of slicing with the cutting edge as you would with a carving knife not just straight chopping, this is where wrist and body motion comes into play to guide the tool in a direction be it curved or straight, that gives the clean 'slice' of the shaving. The actual form of the tool cutting edge, nose etc. obviously has an influence on the optimum approach, this will come with practice in the form of less juddering or vibration and noise.

 

[Keithie]

Thanks Chas ... It's all skill building for me at the moment ... Three dimensions of tool movement plus rotation of tool plus rate of cut plus effects of bevel shape ...before even starting to consider the character of the wood and flexible objectives!

I think I kinda understand the slicing thing as being different from a push type cut. It seems I can sometimes plane down the internal curve pretty nicely with the bowl gouge when it's sharp (akin to a skew planing the surface of a cylinder of wood) ...so I guess that might be what you mean by slicing ?

I'm still thinking about bowl gouge bevel shape ...might take some time in my case !

Am I right in assuming that no-one really adjusts the 3D bevel shape to fit the project ... And instead it's much more about a choice of sweep shape rather than curve from tip to underside ? ..in practice the changing radius (assuming there is one) of what is being cut is managed by tool rotation / other manipulation?

 

[CHJ]

No don't attempt to keep changing the bevel, what you will find is that a couple of gouges with differing (steeper) nose angle will give you easier access to the bottom of the deeper bowls. Outside that it's a case of rotating and angling the tool to keep the bevel in contact and travelling in the desired direction.

Don't over analyse bevels and tool forms, stick with one that works for you and practice, sooner or later you may feel that if the bevel was steeper or shallower you might get on with it better, then try it and you will have past experience to compare it with.
You may find it better, you may find it worse or comes with its own problems, no problem, at least you will appreciate why for practical reasons and saved yourself a lot of theorising about a subject you have little user knowledge of.


See this Post

 

[Keithie]

Thanks again, and indeed for the link as well.

I guess I like to figure out why my bowl gouge is slapping around inside my badly formed bowl and taking chunks out of it ..lol...though it's happening much less!

Sticking with the bevel I have and persisting definitely sounds the best way.. I might have a go with some shallower bowls as most I've tried are quite steep sided with sharpish transition towards the end (I had in mind to try and stick to y=1/x internal and external curves for bowls as I quite like that form ...but that won't always suit the wood I happen to have)

Cheers